Image forming apparatus, method for controlling thereof, and storage medium

ABSTRACT

An image forming apparatus includes a detection unit configured to detect an object, a reception unit configured to receive an operation of a user, and a shifting unit configured to shift, if the detection unit detects an object, a power state of the image forming apparatus from a first power state to a second power state different from the first power state, and shift, if the reception unit receives an operation of a user, the power state of the image forming apparatus from the second power state to the first power state.

FIELD

Aspects of the present invention generally relate to an image formingapparatus having a sensor for detecting an object such as a person.

DESCRIPTION OF THE RELATED ART

Techniques for returning from a power-saving state when an image formingapparatus detects an object such as a person with a sensor provided inthe image forming apparatus are known (see Japanese Patent ApplicationLaid-Open No. 2012-118253). The image forming apparatus discussed inJapanese Patent Application Laid-Open No. 2012-118253 includes a sensorfor detecting a moving object existing within a predetermined rangearound the image forming apparatus. When the sensor detects the movingobject, the image forming apparatus shifts from a power-saving state toa standby state in which the power consumption amount is larger thanthat in the power-saving state.

The image forming apparatus discussed in Japanese Patent ApplicationLaid-Open No. 2012-118253 includes, in addition to the above-describedsensor, a power-saving button for shifting the power state in the imageforming apparatus from the power-saving state to the standby state. Inresponse to a pressing operation of the power-saving button by a user,the image forming apparatus shifts from the power-saving state to thestandby state.

In some cases, the power-saving button has also a function, in additionto the function for shifting the power state in an image formingapparatus to return from the power-saving state to the standby state,for shifting the power state in the image forming apparatus from thestandby state to the power-saving state (see Japanese Patent ApplicationLaid-Open No. 2012-248961). In a state where a value of a power moderegister indicating a power state in an image forming apparatus is “001”(indicating that the image forming apparatus is in a power-savingstate), if the power-saving button is pressed, the image formingapparatus shifts the power state in the image forming apparatus from thepower-saving state to the standby state. In a state where a value of thepower mode register indicating a power state in the image formingapparatus is “010” (indicating that the image forming apparatus is inthe standby state), if the power-saving button is pressed, the imageforming apparatus shifts the power state in the image forming apparatusfrom the standby state to the power-saving state.

In such an image forming apparatus that shifts from the power-savingstate to the standby state in response to the detection of an objectsuch as a person by the sensor, after the detection of the object suchas a person by the sensor, the image forming apparatus takes apredetermined period of time to return from the power-saving state tothe standby state. This is because the device to which the power supplyhas started needs a predetermined time for the boot processing. Due tothe booting operation, when the user arrives in front of the imageforming apparatus, in some cases, the image forming apparatus has notreturned to the standby state. In such a case, the user who has arrivedin front of the image forming apparatus may mistakenly think that theimage forming apparatus has not returned to the standby state, and pressthe power-saving button to instruct the image forming apparatus toreturn from the power-saving state to the standby state.

However, if the power-saving button is pressed while the image formingapparatus is shifting from the power-saving state to the standby statein response to the detection of the object by the sensor, the imageforming apparatus determines that the pressing operation of thepower-saving button is an instruction for shifting from the standbystate to the power-saving state. This is because, at the time the objectsuch as a person is detected by the sensor, the value of the power moderegister in the image forming apparatus becomes to “010”, and when thevalue of the register is “010”, the power-saving button is pressed. As aresult, after the shift from the power-saving state to the standbystate, the image forming apparatus immediately shifts to thepower-saving state.

SUMMARY

Aspects of the present invention are generally directed to an imageforming apparatus capable of preventing an image forming apparatus fromunnecessarily shifting to the power-saving state even if a power-savingbutton is pressed while the image forming apparatus is returning fromthe power-saving state in response to the detection of an object by asensor.

According to an aspect of the present invention, an image formingapparatus includes a detection unit configured to detect an object, areception unit configured to receive an operation of a user, and ashifting unit configured to shift, if the detection unit detects anobject, the power state of the image forming apparatus from a firstpower state to a second state different from the first power state, andshift, if the reception unit receives an operation of a user, the powerstate in the image forming apparatus from the second power state to thefirst power state. The shifting unit, after detection of the object,according to the operation of the user received during the shift of theimage forming apparatus to the second power state, prevents the imageforming apparatus from shifting from the second power state to the firstpower state.

Further features of the present disclosure will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view illustrating an image forming apparatus accordingto a first exemplary embodiment.

FIG. 2 is a plan view illustrating the image forming apparatus.

FIG. 3 is a hardware block diagram illustrating the image formingapparatus.

FIG. 4 is a block diagram illustrating a power system in the imageforming apparatus.

FIG. 5 is a block diagram illustrating a power control unit in the imageforming apparatus in detail.

FIG. 6 is a power transition diagram of the image forming apparatus.

FIGS. 7A, 7B, 7C, and 7D illustrate detection states of a sensor in theimage forming apparatus.

FIG. 8 is a flowchart illustrating an operation performed by the powercontrol unit in a case where an interruption is issued by the sensor.

FIG. 9 is a flowchart illustrating an operation performed by the powercontrol unit in a case where an interruption is issued via thepower-saving button.

FIG. 10 is a flowchart illustrating an operation performed by the powercontrol unit in a case where an interruption due to another condition isissued.

FIG. 11 is a flowchart illustrating an operation performed by the powercontrol unit in a case where an interruption is issued by a sensor in animage forming apparatus according to a second exemplary embodiment.

FIG. 12 is a plan view illustrating an image forming apparatus accordingto a third exemplary embodiment.

FIG. 13 is a hardware block diagram illustrating the image formingapparatus according to the third exemplary embodiment.

DESCRIPTION OF THE EMBODIMENTS

Various exemplary embodiments will be described in detail below withreference to the drawings.

<Brief Description of Image Forming Apparatus>

As illustrated in FIG. 1, an image forming apparatus 100 according to afirst exemplary embodiment is a multi-function peripheral (MFP) having aplurality of functions such as a copying function, a print function, ascanning function, and a facsimile function. In the present exemplaryembodiment, as an example, the MFP is employed, however, the presentexemplary embodiment is not limited to the MFP, and a single functionperipheral (SFP) may be employed. The image forming apparatus 100 isconnected to a communication network such as the Internet. The imageforming apparatus 100 can, through the communication network,communicate with a single or a plurality of external devices 101 such asa personal computer (PC). The image forming apparatus 100 is connectedto a telephone network. The image forming apparatus 100 can, through thetelephone network, perform facsimile reception and facsimiletransmission.

The image forming apparatus 100 according to the first exemplaryembodiment includes a sensor 610 for detecting the approach of an objectsuch as a person to the image forming apparatus 100. The sensor 610 candetect objects including living things such as humans and animals, andlifeless things such as robots. When the sensor detects an object suchas a person, the image forming apparatus 100 shifts from a power-savingstate (the first power state) (S2) to a standby state (the second powerstate) (S1). The power states in the image forming apparatus 100 will bedescribed below.

As illustrated in FIG. 1 and FIG. 2, the sensor 610 is mounted on thefront side of the image forming apparatus 100. To detect an objectexisting in front of the image forming apparatus 100, the sensor 610 hasa detection range SA in front of the image forming apparatus 100.

As illustrated in FIG. 3, the image forming apparatus 100 includes acontroller unit 200, a fax unit 300, an auto document feeder (ADF) 400,an operation unit 500, a sensor unit 600, a local area network (LAN)controller 700, a storage 800, a printer control unit 900, a printerunit 910, a scanner control unit 920, and a scanner unit 930.

<About Controller Unit 200>

The controller unit 200 controls operation of each unit in the imageforming apparatus 100. The controller unit 200 includes a centralprocessing unit (CPU) 210, a read-only memory (ROM) 220, a random accessmemory (RAM) 230, an image rendering unit 240, a timer 250, and a powercontrol unit 260.

The CPU 210 executes a software program for controlling the controllerunit 200.

The ROM 220 stores a boot program of the image forming apparatus 100,various setting values, and other data.

The RAM 230 temporarily stores data to be used by the software programto be executed by the CPU 210.

The image rendering unit 240 performs image processing such as colorspace conversion on the image data read by the scanner unit 930 and theimage data generated based on a page description language (PDL) datareceived from an external device 101. The image rendering unit 240converts the image-processed image data into bitmap data. The bitmapdata is output to the printer unit 910. The printer unit 910 forms animage on a sheet based on the bitmap data.

The timer 250 measures a period of time.

The power control unit 260 controls supply and interruption of theelectric power to each unit in the image forming apparatus 100. Thepower control unit 260 will be described in detail below.

<About Fax Unit 300>

The fax unit 300, through the telephone network, performs facsimilereception and facsimile transmission. The fax unit 300 includes a CPU301, a ROM 302, a RAM 303, a modem 304, and a reception detection unit305.

The CPU 301 controls transmission and reception of a facsimile incooperation with the controller unit 200.

The ROM 302 stores a boot program of the fax unit 300, various settingvalues, and other data.

The RAM 303 temporarily stores data to be used by the software programto be executed by the CPU 301.

The modem 304 performs modulation for the reception and transmission ofa facsimile.

The reception detection unit 305 detects reception of a facsimile. Thereception detection unit 305, in response to the reception of thefacsimile, sends an interruption signal Interrupt_F to the power controlunit 260.

<About ADF 400>

The ADF 400 automatically feeds a document to a document reading unit(not illustrated) of the scanner unit 930. The ADF 400 includes adocument detection sensor 401 for detecting a document that is set. Thedocument detection sensor 401, in response to the detection of theplacement of a document, sends an interruption signal Interrupt_D to thepower control unit 260.

<About Operation Unit 500>

The operation unit 500 includes a display unit 510 and various keys 520.

The display unit 510 displays a status screen for displaying a status ofthe image forming apparatus 100, a setting screen for inputtinginformation necessary to perform the copy function and the facsimilefunction.

As illustrated in FIG. 2, the various keys 520 include numeric keypads521, a start key 522, and a power-saving button 523. The power-savingbutton 523 is provided to shift the power state of the image formingapparatus 100. The power-saving button 523 receives an operation of auser. When the user presses the power-saving button 523 in a state wherethe image forming apparatus 100 is in the power-saving state (S2), theimage-forming apparatus 100 shifts from the power-saving state (S2) tothe standby state (S1). When the user presses the power-saving button523 in a state the image forming apparatus 100 is in the standby state(S1), the image-forming apparatus 100 shifts from the standby state (S1)to the power-saving state (S2). When the power-saving button 523 ispressed, to the power control unit 260, an interruption signalInterrupt_O is sent.

<About Sensor Unit 600>

As illustrated in FIG. 3, the sensor unit 600 includes theabove-mentioned sensor 610, and a control circuit 620 for analyzing adetection result of the sensor 610. The sensor 610 is an infrared arraysensor having a plurality of detection units arranged in matrix. Eachdetection unit is a passive sensor that receives infrared light emittedfrom a heat source such as a person, converts the received infraredlight into an electrical signal, and outputs the signal. The detectionunit according to the present exemplary embodiment is an element fordetecting infrared light based on a pyroelectric effect. The detectionunit used in the sensor 610 is not limited to the above-describedpassive sensor, and alternatively, an active sensor that emits infraredlight to an object and receives the light reflected from the object maybe employed. The control circuit 620, based on the electrical signalsoutput from the individual units in the sensor 610, determines whetherthe object has approached the image forming apparatus 100. When thecontrol circuit 620 determines that the object has approached the imageforming apparatus 100, the control circuit 620 outputs an interruptionsignal Interrupt_S to the power control unit 260. FIG. 7A illustrates astate where none of the plurality of the detection units has detected anobject. FIG. 7B illustrates a state where a part of the detection units(in FIG. 7B, five detection units) have detected an object. FIG. 7Cillustrates a state where a part of the detection units (in FIG. 7C,eleven detection units) have detected an object. The control circuit 620according to the first exemplary embodiment, when 10 or more detectionunits have detected an object, determines that the object has approachedthe image forming apparatus 100. Then, the control circuit 620 outputsan interruption signal Interrupt_S to the power control unit 260. In thepresent exemplary embodiment, when 10 or more detection units detect anobject, the control circuit 620 determines that the object hasapproached the image forming apparatus 100, however, the number of thedetection units for detecting an object is not limited to 10. Further,even though the number of the detection units for detecting an object isequal to or greater than 10, as illustrated in FIG. 7D, when thedetection units detecting the object are not adjacent to each other, thecontrol circuit 620 does not determine that the object has approachedthe image forming apparatus 100.

The sensor 610 is not limited to the above-described infrared arraysensor. For example, the sensor 610 may be an infrared line sensor thathas infrared sensors arranged in line. Alternatively, the sensor 610 maybe a pyroelectric array sensor that has pyroelectric sensors arranged inmatrix, and determine the existence of a person by detecting infraredlight emitted from the person and based on the amount of shift.Alternatively, the sensor 610 may be a pyroelectric line sensor that haspyroelectric sensors arranged in line. The sensor 610 may include theabove-described infrared sensor and pyroelectric sensor. As the sensor610, a camera may be used. In the method of determining whether anobject has approached the image forming apparatus 100, as describedabove, when the elements of a predetermined number detect the object, itis determined that the object has approached the image forming apparatus100.

<About LAN Controller 700>

As illustrated in FIG. 3, the LAN controller 700, via the communicationnetwork, receives data transmitted from the external device 101. To theLAN controller 700, electric power is supplied in the power-saving state(S2). In the power-saving state (S2), when the LAN controller 700receives a packet such as a print request from the external device 101,the LAN controller 700 outputs an interruption signal Interrupu_L to thepower control unit 260. Then, the LAN controller 700 shifts to thestandby state (S1) in which the packet can be processed. The LANcontroller 700 also has a proxy response function for replying to apacket when the LAN controller 700 receives the packet such as aninquiry of a state from the external device 101 while remaining in thepower-saving state (S2).

<About Storage 800>

The storage 800 is a hard disk drive (HDD). As an alternative to theHDD, a solid state drive (SSD) can be used as the storage 800.

<About Printer Control Unit 900>

The printer control unit 900 controls the printer unit 910 for formingan image on recording paper, for example, according to anelectrophotographic method. To the printer control unit 900, electricpower is supplied from a third power supply unit 153 in the power supplydevice 150 described below.

<About Scanner Control Unit 920>

The scanner control unit 920 controls the scanner unit 930 for opticallyreading an image formed on a document. To the scanner control unit 920,electric power is supplied from the third power supply unit 153 in thepower supply device 150 described below.

<About Power Supply Device 150>

The image forming apparatus 100 includes the power supply device 150 forsupplying electric power to the above-described blocks.

As illustrated in FIG. 4, the power supply device 150 converts thealternating voltage supplied from an alternating-current power supply Pinto the direct voltage, and supplies the electric power to each unit inthe image forming apparatus 100. The power supply device 150 includes afirst power supply unit 151 for generating the voltage of 3.3 V, asecond power supply unit 152 for generating the voltage of 12 V, and thethird power supply unit 153 for generating the voltage of 24 V. Thepower supply device 150 includes a relay 154 for switching between inputand interruption of the alternating voltage to the second power supplyunit 152, and a relay 155 for switching between input and interruptionof the alternating voltage to the third power supply unit 153. The powercontrol unit 260 in the controller unit 200 switches between the onstate and the off state of the relay 154 and the relay 155.Specifically, the power control unit 260, to the relay 154, outputs aRelay_ON signal to set the relay 154 to the on state, and outputs aRelay_OFF signal to set the relay 154 to the off state. The powercontrol unit 260, to the relay 155, outputs a Relay_ON signal to set therelay 155 to the on state, and outputs a Relay_OFF signal to set therelay 155 to the off state.

Between the above-described power supply units (the first power supplyunit 151, the second power supply unit 152, and the third power supplyunit 153) and the alternating-current power supply P, a switch 156 isprovided. The user can switch the on state and the off state of theswitch 156. When the user sets the switch 156 to the on state, electricpower is supplied from the alternating-current power supply P to theimage forming apparatus 100. When the user sets the switch 156 to theoff state, electric power being supplied from the alternating-currentpower supply P to the image forming apparatus 100 is interrupted.

The first power supply unit 151 supplies generated voltage to the powercontrol unit 160 in the controller unit 200, and the RAM 230. The firstpower supply unit 151 also supplies the generated voltage to the sensorunit 600, the LAN controller 700, the power-saving button 523 in theoperation unit 500, the document detection sensor 401 in the ADF 400,and the reception detection unit 305 in the fax unit 300.

The second power supply unit 152 supplies the generated voltage to theCPU 210, the ROM 220, and the image rendering unit 240 in the controllerunit 200. The second power supply unit 152 also supplies the generatedvoltage to parts (for example, a backlight (not illustrated)) other thanthe power-saving button 523 in the operation unit 500. The second powersupply unit 152 also supplies the generated voltage to parts other thanthe document detection sensor 401 in the ADF 400, and parts (the CPU301, the ROM 302, the RAM 303, and the modem 304) other than thereception detection unit 305 in the fax unit 300.

The third power supply unit 153 supplies the generated voltage to theprinter control unit 900 and the scanner control unit 920.

<About Power Control Unit 260>

Referring to FIG. 5, the power control unit 260 is described in detail.

The power control unit 260 is a complex programmable logic device(CPLD).

The power control unit 260 includes an interruption signal input unit261, a power mode register (hereinafter, referred to as register) 262, aflag (variable) 263, a power control signal output unit 264, and a powermanagement unit 265. When the power control unit 260 receives theabove-described interruption signals Interrupt_S, Interrupt_L,Interrupt_O, Interrupt_D, or Interrupt_F, depending on the value of theregister 262, performs power control of each unit in the image formingapparatus 100.

The interruption signal input unit 261 receives the above-describedinterruption signals Interrupt_S, Interrupt_L, Interrupt_O, Interrupt_D,or Interrupt_F.

The register 262 stores the information indicating a power state of theimage forming apparatus 100. Specifically, when the power state of theimage forming apparatus 100 is in the standby state (S1), “010” is setto the register 262. When the power state of the image forming apparatus100 is in the power-saving state (S2), “001” is set to the register 262.When the power state of the image forming apparatus 100 is in thepower-off state (S3), “100” is set to the register 262.

To a flag 263, the information indicating whether to enable theinterruption signal Interrupt_O from the power-saving button 523 is set.Specifically, when the flag 263 is set to “00”, the power managementunit 265 ignores the interruption signal Interrupt_O from thepower-saving button 523. On the other hand, when the flag 263 is set to“11”, the power control signal output unit 264, in response to theinterruption signal Interrupt_O from the power-saving button 523,outputs the Relay_ON signal or the Relay_OFF signal.

The power control signal output unit 264 outputs the Relay_ON signal orthe Relay_OFF signal.

The power management unit 265, when the interruption signal input unit261 receives an interruption signal, based on the information indicatedby the register 262 and the flag 263, controls the power control signaloutput unit 264 to output the Relay_ON signal or the Relay_OFF signal.

<Power Transition Diagram of Image Forming Apparatus 100>

FIG. 6 is a power transition diagram of the image forming apparatus 100.The image forming apparatus 100 has three states of the standby state(S1), the power-saving state (S2), and the power-off state (S3).

In the standby state (S1), electric power is supplied to each unit suchas the printer unit 910 and the scanner unit 930 in the image formingapparatus 100. In the standby state, printing by the printer unit 910and reading of a document by the scanner unit 930 can be performed. Inthe standby state (S1), the relay 154 and the relay 155 are in the onstate. In this state, electric power is supplied, from the second powersupply unit 152, to the CPU 210, the ROM 220, the image rendering unit240, the operation unit 500 (except for the power-saving button 523),the ADF 400 (except for the document detection sensor 401), the fax unit300 (except for the reception detection unit 305), and the storage 800.In the standby state (S1), electric power is supplied from the thirdpower supply unit 153 to the printer control unit 900 and the scannercontrol unit 920. In the standby state (S1), electric power is suppliedfrom the first power supply unit 151 to the sensor unit 600, the LANcontroller 700, the power-saving button 523 in the operation unit 500,the document detection sensor 401 in the ADF 400, and the receptiondetection unit 305 in the fax unit 300.

In the power-saving state (S2), the power consumption amount is smallerthan that in the standby state (S1). In the power-saving state (S2), thepower supply to the printer unit 910 and the scanner unit 930 in theimage forming apparatus 100 is stopped. In the power-saving state,printing by the printer unit 910 and reading of a document by thescanner unit 930 cannot be performed. In the power-saving state (S2),the relay 154 and the relay 155 are in the off state. In this state,power supply from the second power supply unit 152 and the third powersupply unit 153 is stopped. In the power-saving state (S2), electricpower is supplied from the first power supply unit 151 to the RAM 230,the power control unit 260, the sensor unit 600, the LAN controller 700,the power-saving button 523 in the operation unit 500, the documentdetection sensor 401 in the ADF 400, and the fax unit 300.

In the power-saving state (S2), when one of the following conditions forshifting to the standby-state (S1) is satisfied, the power-saving state(S2) is shifted to the standby state (S1).

The sensor 610 has detected an object.

The power-saving button 523 has been pressed.

The LAN controller 700 has received data such as a print request.

The reception detection unit 305 in the fax unit 300 has received afacsimile.

The document detection sensor 401 in the ADF 400 has detected adocument.

In the standby state (S1), when one of the following conditions forshifting to the power-saving state (S2) is satisfied, the standby state(S1) is shifted to the power-saving state (S2).

A predetermined period of time has passed without receiving data such asa print request by the LAN controller 700.

A predetermined period of time has passed without operation of theoperation unit 500.

The power-saving button 523 has been pressed.

In the image forming apparatus 100 according to the present exemplaryembodiment, when one of the above-described conditions is satisfied, theimage forming apparatus 100 may shift from the standby state (S1) to thepower-saving state (S2). Above-described conditions are just examples.For example, when the LAN controller 700 has not received data such as aprint request and a predetermined time has elapsed without operation ofthe operation unit 500, the image forming apparatus 100 may shift to thepower-saving state (S2).

In the power-off state (S3), the power consumption amount is smallerthan that in the power-saving state (S2). In the power-off state (S3),the switch 156 is turned off by the user. In this state, power supply toeach unit in the image forming apparatus 100 is stopped.

In the standby state (S1) or the power-saving state (S2), when the userturns off the switch 156, the image forming apparatus 100 enters thepower-off state (S3). In the power-off state (S3), when the user turnson the switch 156, the image forming apparatus 100 enters the standbystate (S1). In the power-off state (S3), when the user turns on theswitch 156, the image forming apparatus 100 may enter the power-savingstate (S2).

The image forming apparatus 100 may be in any power state other than theabove-described three power states. For example, the image formingapparatus 100 may enter, other than the above-described power states, asuspend state, and a hibernation state. In the suspend state, the imageforming apparatus 100 can return to the standby state (S1) at highspeed. In the suspend state, the power supply to the RAM 230 ismaintained. The image forming apparatus 100 starts up to the standbystate (S1) using the state of the image forming apparatus 100 stored inthe RAM 230. Also in the hibernation state, the image forming apparatus100 can return to the standby state (S1) at high speed. In thehibernation state, the power state is similar to that in the power-offstate (S3), and the power supply to each unit in the image formingapparatus 100 is stopped. The hibernation state is different from thepower-off state (S3) in that prior to the shift to the hibernationstate, the state of the image forming apparatus 100 is stored in thestorage 800. In returning from the hibernation state to the standbystate (S1), the image forming apparatus 100 returns at high speed basedon the information stored in the storage 800.

<About Operation Performed by Power Control Unit 260 when Interruptionis Issued by Sensor 610>

Referring to FIG. 8, an operation performed by the power control unit260 when an interruption is issued by the sensor 610 is described. Thefollowing operation is executed by the power control unit 260 byexecuting a program according to the flowchart in FIG. 8.

In step S100, when the sensor 610 detects an object and the controlcircuit 620 determines that the object has approached the image formingapparatus 100, an interruption signal Interrupt_S by the sensor 610 isinput to the power control unit 260. In step S101, the power controlunit 260 to which the interruption signal Interrupt_S has been inputchecks the value of the register 262. If the value of the register 262is “010” (the information indicating that the power state in the imageforming apparatus 100 is the standby state (S1)) (NO in step S101), theprocessing in the power control unit 260 ends. If the value of theregister 262 is “001” (the information indicating that the power statein the image forming apparatus 100 is the power-saving state (S2)) (YESin step S101), in step S102, the interruption by the power-saving button523 is disabled. Specifically, the power management unit 265 in thepower control unit 260 sets the flag 263 to “00”. By the operation, aninterruption from the power-saving button 523 is prevented while theimage forming apparatus 100 is returning from the power-saving state tothe standby state. In step S103, the power control unit 260 outputs theRelay_ON signal to the relay 154 and the relay 155. Through theoperation, the relay 154 and the relay 155 enter the on state, electricpower is supplied from the second power supply unit 152 to the CPU 210and other units, and also electric power is supplied from the thirdpower supply unit 153 to the printer control unit 900 and other units.The above-described “disabling the interruption by the power-savingbutton 523” means that even though an interruption signal Interrupt_O isinput through the power-saving button 523, the power management unit 265performs control to ignore the signal Interrupt_O. In the operation of“disabling the interruption by the power-saving button 523”, control maybe performed so as not to input the interruption signal Interrupt_O inthe power control unit 260.

In step S104, the power control unit 260 determines whether the powerstate in the image forming apparatus 100 has entered the standby state(S1). Specifically, when the power control unit 260 is notified from theCPU 210 that the power state in the image forming apparatus 100 hasentered the standby state (S1), the power control unit 260 determinesthat the power state of the image forming apparatus 100 has entered thestandby state (S1) (YES in step S104). When the power control unit 260is notified from the CPU 210 that the power state in the image formingapparatus 100 has entered the standby state (S1) (YES in step S104), instep S105, the power control unit 260 sets the value of the register 262to “010”. Then, the power control unit 260 releases the disable state ofthe interruption by the power-saving button 523. Specifically, in stepS106, the power control unit 260 sets the flag 263 to “11”.

<About Operation Performed by Power Control Unit 260 when Interruptionis Issued Via Power-Saving Button 523>

Referring to FIG. 9, an operation performed by the power control unit260 when an interruption is issued via the power-saving button 523 isdescribed. The following operation is executed by the power control unit260 executing the program according to the flowchart in FIG. 9.

In step S200, when the power-saving button 523 is pressed, theinterruption signal Interrupt_O via the power-saving button 523 is inputin the power control unit 260. In step S201, the power control unit 260to which the interruption signal Interrupt_O has been input determineswhether the interruption by the power-saving button 523 has beendisabled. Specifically, the power control unit 260 determines whetherthe flag 263 has been set to “00”. If the flag 263 has been set to “00”(YES in step S201), the processing in the power control unit 260 ends.

If the flag 263 has been set to “11” (NO in step S201), in step S202,the power control unit 260 checks the value of the register 262. If thevalue of the register 262 is “010” (the information indicating that thepower state in the image forming apparatus 100 is the standby state(S1)) (NO in step S202), in step S203, the power control unit 260outputs the Relay_OFF signal to each of the relay 154 and the relay 155.By the operation, the relay 154 and the relay 155 enter the off state,the electric power supplied from the second power supply unit 152 to theCPU 210 and other units is stopped, and also the electric power suppliedfrom the third power supply unit 153 to the printer control unit 900 andother units is stopped. In step S204, the power control unit 260 setsthe value of the register 262 to “001”. Specifically, when the powercontrol unit 260 is notified from the CPU 210 that the power state inthe image forming apparatus 100 is in the power-saving state (S2), thepower control unit 260 sets the value of the register 262 to “001”.

If the value of the register 262 is “001” (the information indicatingthat the power state in the image forming apparatus 100 is thepower-saving state (S2)) (YES in step S202), in step S205, the powercontrol unit 260 outputs the Relay_ON signal to the relay 154 and therelay 155. Through the operation, the relay 154 and the relay 155 enterthe on state, electric power is supplied from the second power supplyunit 152 to the CPU 210 and other units, and also electric power issupplied from the third power supply unit 153 to the printer controlunit 900 and other units. In step S206, the power control unit 260 setsthe value of the register 262 to “010”. Specifically, when the powercontrol unit 260 is notified from the CPU 210 that the power state inthe image forming apparatus 100 is in the standby state (S1), the powercontrol unit 260 sets the value of the register 262 to “010”.

In the first exemplary embodiment, while the image forming apparatus 100is returning from the power-saving state (S2) by an interruption fromthe sensor 610, even if the power-saving button 523 is pressed, theimage forming apparatus 100 can be prevented from shifting to thepower-saving state (S2).

<About Operation Performed by Power Control Unit 260 when Interruptionis Issued Due to Other Conditions>

Referring to FIG. 10, an operation of the power control unit 260 to beperformed when an interruption (one of the following three conditions)other than the interruption by the sensor 610 and the interruption viathe power-saving button 523 is issued, is described. The followingoperation is executed by the power control unit 260 executing theprogram according to the flowchart in FIG. 10.

When the LAN controller 700 receives a specific packet such as a printrequest from the external device 101 (i.e., an interruption signalInterrupt_O is input to the power control unit 260).

The document detection sensor 401 detects a document (i.e., aninterruption signal Interrupt_D is input to the power control unit 260).

The reception detection unit 305 receives facsimile data (i.e., aninterruption signal Interrupt_F is input to the power control unit 260).

In step S300, when the above-described interruption is issued, in stepS301, the power control unit 260 checks the value of the register 262.If the value of the register 262 is “010” (the information indicatingthat the power state in the image forming apparatus 100 is the standbystate (S1) (NO in step S301), the processing by the power control unit260 ends. If the value of the register 262 is “001” (the informationindicating that the power state in the image forming apparatus 100 isthe power-saving state (S2)) (YES in step S301), in step S302, the powercontrol unit 260 outputs the Relay_ON signal to the relay 154 and therelay 155. Through the operation, the relay 154 and the relay 155 enterthe on state, electric power is supplied from the second power supplyunit 152 to the CPU 210 and other units, and also electric power issupplied from the third power supply unit 153 to the printer controlunit 900 and other units. In step S303, the power control unit 260 setsthe value of the register 262 to “010”. Specifically, when the powercontrol unit 260 is notified from the CPU 210 that the power state inthe image forming apparatus 100 is in the standby state (S1), the powercontrol unit 260 sets the value of the register 262 to “010”.

In the first exemplary embodiment, when the image forming apparatus 100returns to the standby state (S1), the disable state of an interruptionby the power-saving button 523 is released. In a second exemplaryembodiment, after the interruption by the power-saving button 523 isdisabled, when a predetermined period of time has passed, the disablestate of the power-saving button 523 is released.

With reference to FIG. 11, an operation performed by the power controlunit 260 when an interruption is issued by the sensor 610 is described.The following operation is executed by the power control unit 260executing a program according to the flowchart in FIG. 11.

In step S400, when the sensor 610 determines that the object hasapproached the image forming apparatus 100, an interruption signal bythe sensor 610 is input to the power control unit 260. In step S401, thepower control unit 260 to which the interruption signal has been inputchecks the value of the register 262. If the value of the register 262is “010” (the information indicating that the power state in the imageforming apparatus 100 is the standby state (S1)) (NO in step S401), theprocessing by the power control unit 260 ends. If the value of theregister 262 is “001” (the information indicating that the power statein the image forming apparatus 100 is the power-saving state (S2)) (YESin step S401), in step S402, the interruption by the power-saving button523 is disabled. Specifically, in step S402, the power control unit 260sets the flag 263 of the power control unit 260 to “00”. In step S403,the power control unit 260 outputs the Relay_ON signal to the relay 154and the relay 155. Through the operation, the relay 154 and the relay155 enter the on state, electric power is supplied from the second powersupply unit 152 to the CPU 210 and other units, and also electric poweris supplied from the third power supply unit 153 to the printer controlunit 900 and other units.

In step S404, the power control unit 260, after disabling theinterruption by the power-saving button 523, determines whether apredetermined period of time has passed. Specifically, if the powercontrol unit 260 determines that a predetermined period of time haspassed (YES in step S404), in step S405, the power control unit 260 setsthe value of the register 262 to “010”. Then, the power control unit 260releases the disable state of the interruption via the power-savingbutton 523. Specifically, in step S406, the power control unit 260 setsthe flag 263 of the power control unit to “11”.

In the above-described first exemplary embodiment, the infrared arraysensor is used as the sensor 610. A sensor unit 1600 in an image formingapparatus 1000 according to a third exemplary embodiment includes aprimary sensor 1611, a secondary sensor 1612, and a control circuit1620.

The primary sensor 1611 detects a motion of an object around the imageforming apparatus 1000. The primary sensor 1611 is an infrared sensorusing a pyroelectric effect of a pyroelectric element. The detectionrange SA of the primary sensor 1611 is wider than the detection range SBof the secondary sensor 1612. When a motion of an object such as aperson is detected in the detection range SA of the primary sensor 1611,the primary sensor 1611 outputs a detection signal to a control circuit1620. When the primary sensor 1611 detects the motion of the object,electric power is supplied to the secondary sensor 1612. Through theoperation, the secondary sensor 1612 starts detection operation of anobject.

The secondary sensor 1612 detects existence of an object such as aperson. The secondary sensor 1612 is a reflection type infrared sensorhaving an output unit for outputting infrared light, and a lightreception unit for receiving the reflected light of the infrared lightoutput from the output unit. The detection range SB of the secondarysensor 1612 is smaller than the detection range SA of the primary sensor1611. When the secondary sensor 1612 detects existence of an object, thesecondary sensor 1612 outputs a detection signal to a control circuit1620. If the secondary sensor 1612 detects the existence of the object,the control circuit 1620 outputs the interruption signal Interrupt_S bythe sensor to the power control unit 260.

The operation of the power control unit 260 that has received theinterruption signal Interrupt_S is similar to that in FIG. 8 accordingto the first exemplary embodiment, and consequently, the descriptionthereof is omitted.

Other Exemplary Embodiments

While the present disclosure has made reference to exemplaryembodiments, it is to be understood that these specific exemplaryembodiments are not seen to be limiting, and various modifications canbe made without departing from the scope of the disclosure. Further, apart of the above-described exemplary embodiments may be combined witheach other as needed.

In the above-described exemplary embodiments, the power control unit 260executes the program to implement each step in FIG. 8, FIG. 9, and FIG.10. Alternatively, the implementation of each step can be made with ahardware logic circuit.

The functions illustrated in the flowcharts in the exemplary embodimentscan be implemented by executing software (program) acquired via anetwork or various storage media using a processing device (CPU orprocessor) in a personal computer (computer) or other devices.

According to the above-described exemplary embodiments, even if thepower-saving button is pressed while the image forming apparatus isreturning from the power-saving state, in response to the detection ofan object with the sensor, unnecessary shift in the image formingapparatus to the power-saving state can be prevented.

Other Embodiments

Additional embodiments can also be realized by a computer of a system orapparatus that reads out and executes computer executable instructionsrecorded on a storage medium (e.g., computer-readable storage medium) toperform the functions of one or more of the above-describedembodiment(s) of the present invention, and by a method performed by thecomputer of the system or apparatus by, for example, reading out andexecuting the computer executable instructions from the storage mediumto perform the functions of one or more of the above-describedembodiment(s). The computer may comprise one or more of a centralprocessing unit (CPU), micro processing unit (MPU), or other circuitry,and may include a network of separate computers or separate computerprocessors. The computer executable instructions may be provided to thecomputer, for example, from a network or the storage medium. The storagemedium may include, for example, one or more of a hard disk, arandom-access memory (RAM), a read only memory (ROM), a storage ofdistributed computing systems, an optical disk (such as a compact disc(CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flashmemory device, a memory card, and the like.

While the present disclosure has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2013-078434 filed Apr. 4, 2013, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An image forming apparatus comprising: adetection unit configured to detect an object; a reception unitconfigured to receive an operation of a user; and a shifting unitconfigured to shift, if the detection unit detects an object, a powerstate of the image forming apparatus from a first power state to asecond power state different from the first power state, and shift, ifthe reception unit receives an operation of a user, the power state ofthe image forming apparatus between the second power state and the firstpower state, wherein the shifting unit, in a case where the receptionunit receives the operation of a user after the detection unit detectsan object and before the power state of the image forming apparatus isshifted to the second power state by the shifting unit in response tosuch detection, does not shift the power state of the image formingapparatus from the second power state to the first power state inresponse to receiving the operation of the user.
 2. The image formingapparatus according to claim 1, further comprising: a storage unitconfigured to store information indicating the power state of the imageforming apparatus, wherein the shifting unit, when the reception unithas received an operation of the user, if the storage unit has storedinformation indicating the first power state, shifts the power state ofthe image forming apparatus from the first power state to the secondpower state, and if the storage unit has stored information indicatingthe second power state, shifts the power state of the image formingapparatus from the second power state to the first power state.
 3. Theimage forming apparatus according to claim 1, further comprising: astorage unit configured to store information indicating whether toenable an interruption by the operation of the user received by thereception unit, wherein the shifting unit, if the information stored inthe storage unit indicates to disable the interruption, after thedetection of the object by the detection unit, according to theoperation of the user received during the shift of the image formingapparatus to the second power state, prevents the image formingapparatus from shifting from the second power state to the first powerstate, and if the information stored in the storage unit indicates toenable the interruption, after the detection of the object by thedetection unit, according to the operation of the user received duringthe shift of the image forming apparatus to the second power state,allows the image forming apparatus to shift from the second power stateto the first power state.
 4. The image forming apparatus according toclaim 1, wherein the detection unit is a sensor having a plurality ofdetection units.
 5. The image forming apparatus according to claim 4,wherein the sensor includes an array-type sensor in which the detectionunits are arranged in a matrix.
 6. The image forming apparatus accordingto claim 1, wherein the detection unit is an infrared sensor forreceiving infrared light.
 7. The image forming apparatus according toclaim 1, wherein, in the first power state, the power consumption amountis less than the power consumption amount in the second power state. 8.The image forming apparatus according to claim 1, further comprising: animage forming unit configured to form an image on a sheet.
 9. The imageforming apparatus according to claim 8, wherein, in the first powerstate, power supplied to the image forming unit is stopped, and in thesecond power state, electric power is supplied to the image formingunit.
 10. A method of controlling an image forming apparatus, the methodcomprising: shifting, in a case where an object is detected, a powerstate in the image forming apparatus from a first power state to asecond power state different from the first power state; shifting, in acase where a user operation is received, the power state in the imageforming apparatus between from the second power state and to the firstpower state; and performing control, in a case where the operation of auser is received after an object is detected and before the power stateof the image forming apparatus is shifted to the second power state inresponse to such detection, the control performed such that the powerstate of the image forming apparatus is not shifted from the secondpower state to the first power state in response to receiving theoperation of the user.
 11. A non-transitory computer-readable storagemedium storing computer executable instructions for causing a computerto perform a method, the method comprising: shifting, in a case where anobject is detected, a power state in the image forming apparatus from afirst power state to a second power state different from the first powerstate; shifting, in a case where a user operation is received, the powerstate in the image forming apparatus between from the second power stateand to the first power state; and performing control, after detection ofthe object, during the shift of shifting, in a case where a useroperation is received, the power state in the image forming apparatusbetween the second power state and the first power state; and performingcontrol, in a case where the operation of a user is received after anobject is detected and before the power state of the image formingapparatus is shifted to the second power state in response to suchdetection, the control performed such that the power state of the imageforming apparatus is not shifted from the second power state to thefirst power state in response to receiving the operation of the user.